Medibank Health Directory

What is diarrhoea?

Diarrhoea involves the frequent passing of watery faeces.

Commonly caused by an infection of the intestines such as gastroenteritis or food poisoning, diarrhoea can be dangerous for young children and the elderly.

Diarrhoea is either acute or chronic. Acute diarrhoea involves three or more loose stools a day for less than two weeks, while chronic diarrhoea lasts for over a month and can be a sign of cancer or an inflammatory bowel condition such as ulcerative colitis or Crohn’s disease.

Acute diarrhoea is common and affects nearly everyone at some point. While statistics are not kept on how many people contract diarrhoea in Australia, it is a serious problem in developing countries, with 2 billion cases reported each year worldwide.

Symptoms of diarrhoea

Symptoms associated with diarrhoea include:

  • an urgent need to go to the toilet
  • frequent passing of watery faeces
  • nausea
  • stomach cramps
  • stomach pains.

It is normal to recover from acute diarrhoea within a day or two. Contact your doctor immediately if you experience serious symptoms including:

  • blood in faeces
  • fever (temperature higher than 38 °C)
  • inability to increase fluid intake
  • painful passage of faeces
  • pus in faeces
  • reduced or absent urination
  • repeated vomiting.

If you have a serious chronic medical condition, such as kidney or heart failure, even one day of diarrhoea can be dangerous – visit your doctor as soon as possible.

If you have recently returned from overseas, it is also recommended you see a doctor quickly as the diarrhoea may not be caused by one of the self limiting viruses common in Australia. In fact, bacteria may be the cause and antibiotics may be required.

Causes of diarrhoea

Diarrhoea is caused by a wide range of disorders, infections and events, including:

  • gastroenteritis
  • anxiety or emotional stress
  • food poisoning
  • overconsumption of alcohol
  • medication, particularly antibiotics
  • tropical diseases, such as cholera and typhoid.

Contaminated food and water are common causes of acute diarrhoea. Some of the infectious agents known to cause diarrhoea are:

  • Bacteria such as E. coli, campylobacter, v. cholerae, shigella, salmonella and staphyloccus aureus.
  • Parasites like giardia lamblia, cryptosporidium parvum and tapeworm.
  • Viruses such as calici virus, adenovirus and rotavirus.

Causes of chronic diarrhoea include:

  • Cancers such as bowel cancer.
  • Chronic constipation where the bowel is blocked by hard, impacted faeces, but some liquid manages to seep past the blockage. This condition, called ‘overflow’ or ‘spurious’ diarrhoea, is most common in the elderly.
  • Coeliac disease which reduces the intestine’s ability to absorb food.
  • Hormone disorders such as diabetes or hyperthyroidism (overactive thyroid gland).
  • Inflammatory bowel disease, including ulcerative colitis and Crohn’s disease.
  • Irritable bowel syndrome, with symptoms such as alternating constipation and diarrhoea, stomach bloating and pain.
  • Lactose intolerance, where the body is unable to digest the milk sugar lactose.

Diagnosis and treatment of diarrhoea

Successful treatment of diarrhoea depends on diagnosing the cause. Investigations may include:

  • Medical history.
  • Physical examination
  • Laboratory analysis of stool sample.
  • Blood tests.
  • Colonoscopy (the insertion of a slender instrument into the anus so that the doctor can look at the bowel lining) to rule out cancer or inflammatory bowel diseases.

Always see your doctor if you experience serious symptoms. Young children and the elderly require prompt medical attention if suffering diarrhoea.

Treatment for diarrhoea depends on the cause, but may include:

  • Anti-diarrhoeal medications
  • Oral rehydration drinks to replace lost salts and minerals.
  • Intravenous replacement of fluids (in severe cases)
  • Medications such as antibiotics and anti-nausea drugs
  • Treatment for any underlying condition, such as inflammatory bowel disease.

Further Information and sources


This article is of a general nature only. You should always seek medical advice if you think you may have symptoms of diarrhoea.